John simon



(ModeL) J. SIMON.

DOOR KNOB ALARM. No. 256,924. Patented Apr. 25, 1882.

INVENTOR' W BY M ATTORNEY UNITED STATES PATENT OFFICE.

JOHN SIMON, OF NEW YORK, N. Y.

DOOR-KNOB ALARM.

SPECIFICATION forming part of Letters Patent No, 256,924, dated. April 25, 1882 Application filed January 16, 1882.

To all whom it may concern:

Be it known that I, JOHN SIMON, of the city, county, and State ofNew York, have invented certain new and useful Improvements in Door- Knob Alarms, of which the followingis a specification.

This invention has reference to an improved alarm-bell which is used in connection with the door-knob and spindle to announce the opening of the door or attempts at opening, the bell being arranged in such a manner that it is sounded when the door is opened or attempted to be opened from the outside, but is not sounded when the door is opened from the inside.

Door-knob alarms have been used heretofore and have been constructed in many differentways, either as an attachment to the door or to the knob itself; but in all these cases they were either inconvenient or unsightly, or they sounded the bell also when the door had to be opened from the inside, which is not necessary in practice, as the alarm should only be sounded when the door is opened or attempted to be opened from the outside.

The invention consists of the combination, in a door-knob alarm, of an alarm mechanism contained within the inner knob, with a bell forming part of such knob, and with mechanism whereby the alarm mechanism is thrown out of contact with the ringing device when the inner knob is turned for opening the door.

It also consists of the combination of a knobspindle, having an inner door-knob formed of a disk and a bell loose on the spindle, and a pawlframe sliding on the spindle and having wings and pawls pivoted thereto, with a striking mechanism and a cam-sleeve having a perforated ear, to which the bell is connected by a fixed pin, the camsleeve being adapted to engage the pawl-frame and move it forward, so as to clear the striking mechanism. 1

The alarm mechanism may also be thrown out of use from the inside by a suitable lever (Model) Fig. 4 is a front view of the inner disk of the inner knob. Fig. 5 is aback view of the parts shown in Fig. 2. Fig. 6 is a face view of the cam-sleeve. Fig. 7 is aperspective view of the part shown in Fig. 6. Fig. 8 is alongitudinal section through the cam-sleeve and a portion ofthe pawl-frame. Fig. 9 shows the inner face of the shell or bell portion of the inner knob.

Similar letters of reference indicate corresponding parts.

The spindle A is square in cross-section, its outer end fitting into a square socket of the outer knob, D, which latter is of any ordinary construction. The inner knob, B, is composed of a cupshaped shell, B, and a disk, E the former serving the purposes both of knob and bell and the latter carrying a portion of. the striking mechanism. The shell B, which is composed of hell metal or other resonant material, turns loosely on the inner rounded end of the spindle A, which passes through a central slot thereof, while the disk B is rigidly connected to the door, being cast in one piece with a tubular shank, O, and-the rose Oat the opposite end of said shank. The diameter of the shell B exceeds that of the disk B so that there is no contact between them, and the former is free to vibrate under the strokes of the bell-hammer.

On the spindle A, adjoining the face of the disk B is arranged a cam-sleeve, E, provided with aperforated car, a. This cam-sleeve hasa round central hole sufficiently large to enable it to turn loosely on the spindle A, andis provided with asidewise-projectingcamorear,a. Immediately in front of the cam-sleeve E is arranged onsaid spindle aslidin g sleeve, F, which serves as a pawl-carrying frame, being provided with laterall y-projectin g ears (I d, to which the pawls G G are pivoted. This sleeve or pawl-frame is provided with recesses into which the tapering cams of the cam-sleeve E project, and with a square central hole whereby it is made to turn with the spindle. The pawls Gr Gr, which are compressed by the spring J, are notched at their outer ends, so as to be engaged by a tongue, f,of the spring actuated striking-hammer H, which is applied to a fixed pivot of the disk B 6 The shell B is connected to the cam-sleeve E by means of a pin, 1), the outer end of which is fixed to the shell, while the inner end projects into the perforated ear a of the sleeve. The pawl-frame F is provided with an areshaped slot, e, through which the pin 1) passes withoutdisturbingtheframe. Aspiral spring, I, is interposed between the pawl'frame and the shell B, serving to press the pawl-frame into contact with the cam-sleeve E. Now, when the spindle is turned from the outside by the outer knob the pawl-frame turns therewith the loose e'am-sleeve E and the bell B, and brings one of the spring-acted pawls G in eontact with the tongue of the hammer, according as the spindle is turned to one side orthe other, and thus the bell is sounded;.but when the door is to he opened from the inside the turning of the hell or shell B causes, by the action of the connecting-pin b, the turning of the cam-sleeve E, whereby the pawl-frame F is forced forward on the spindle,'so that the pawls are thrown clear of the tongue of the ham mer, and consequently the bellis not struck by the same. The cam-sleeve E rotates the pawl-frame F, by which the spindle is turned and the door opened without ringing the bell.

The slot of the pawl-frame for the pin of the alarm-bell B has to be large enough to provide for the turning of the spindle in either direction, so that the pin does not interfere with the sounding mechanism. As soon as the spindle returns to its normal position the pawl-frame also is moved forward by its spiral spring, and thus placed again into position for being sounded by the turning of the spindle from the outside.

For the purpose of throwing out the alarm mechanism entirely, whenever desired, an cecentrically -pivoted cam, K, is arranged in connection with the disk B of the inner knob, said eccentric engaging apin,f, of the tongue endf of the hammer and throwingitin outward direction, so as to correspondingly throw in the hammer. The shaft of the cocentric is operated by a small handle, L, from the outside.

' the door-knob is entirely stored away within the inner knob, being made of a simple and compact construction.

The entire alarm mechanism of In place of the mechanism for throwing out the pawls clear of the tongue of the hammer, a mufiiing device composed of suitable damper-springs may be used, by which the mufflin g of the bell is effected automatically, though for practical purposes I prefer to throw the alarm mechanism entirely out of contact with the striking mechanism, so as to positively prevent the ringing of the bell when the door is opened from the inside, so as to dispense with the disagreeable muffled sound of the bell, and also with any muffling of the bell by the hand.

Having thus described myinvention,Ic1aim asnew and desire to secure by LettersPatent 1. As an improvementindoor-knob alarms, the combination of an alarm mechanism contained within the inner knob with a bell which forms partof such knob, and with mechanism whereby the alarm is thrown out of contact with the ringing device when the inner knob is turned for opening the door, substantially as and for the purpose set forth.

2. The combination of a knob-spindle, an inner knob composed of a disk connected to the door and a bell'loose'on the knob'spindle, a pawl'frame sliding on the knob-spindle and having wings or ears and pawlspivoted thereto, with striking mechanism, and a cam-sleeve having a perforated cam or car, to which the bell is connected by a fixed pin, whereby the cant-sleeve is adapted to engage the pawl-frame and slide it forward clear of the striking mechanism, substantially as set forth.

3. The combination of the fixed disk, the bell, the striking mechanism,an eccentricallypivoted cam on said disk, adapted to engage a pin of the hammer-tongue, and means for turning said cam from the outside of the knob, whereby the striking mechanism may be thrown out of gear at will, substantially as described.

In testimonythatI claim the foregoingas my invention I have signed my name, in presence of two witnesses, this 29th day of July, 1881.

\ JOHN SIMON. Witnesses:

PAUL GoEPEL, CARL KARP. 

